Mandrel changing apparatus



Jan. 18, 1955 mea Feb 7 1951 J. W. KELSO MANDREI.. CHANGING APPARATUSJan. 18, 1955 3 Sheets-Sheet 2 Filed Feb. 7, 1951 Jan. 18, 1955 J. w.KELso 2,699,697

MANDREL CHANGING APPARATUS Filed Feb. 7. 1951 3 Sheets-Sheet 3 Inventar:JH/V l1( KELSO,

United States Patent MANDREL CHANGING APPARATUS John W. Kelso, Clairton,Pa., assignor to United States Steel Corporation, a corporationoiNewJersey` Application February 7, 1951, Serial `Nm 209,750

1 Claim. (Cl. 80-1) This invention relates to apparatusfor mechanicallyhandling and changing thepiercing mandrels in seamless tubing4 mills.

ln operating such mills, the piercing mandrel` must be changed aftereach billet-has been pierced and must be thoroughly cooledbefore-it canybe re-used. It is-,customary to employ three or more mandrels for eachmill, one of which is in usewhile the others are cooling. Usuallymandrels are changed manually, which is a fiatilguing operation,particularly for larger sizes omanre s.

An object of the present invention is to provide improved apparatus formechanically handling and chang ing mandrels and which can be installedon existing mills without otherwise altering the mill or mandrelstructure.

A further object of the invention is to provide a mandrel handlingapparatus which includes mechanical means for gripping a mandrel andcooperating mechanical means for transferring mandrels thus gripped fromthe guide shoe of a piercing mill to a cooling bosh and from said boshto the mandrel trough of the mill.

in accomplishing these and other objects of the invention I haveprovided improved details of structure, a preferred form of which isshown in the accompanying drawings, in which;

Figure l is a top plan view of a portion of a piercing mill which isequipped with a mandrel changing apparatus embodying features of thepresent invention;

Figure 2 is a side elevational view, with parts broken away, of themandrel changing apparatus;

Figure 3 is an end elevational view of the mandrel changing apparatus;and

Figure 4 is a vertical sectional view of a cooling bosh for themandrels.`

The drawing shows a portion of a seamless tubing piercing mill whichincludes the usual rolls and 12, guide shoe 13, and mandrel trough 14.The mill is shown as equipped with four piercing mandrels M1, M2, M3,and Mr. In operation, a cool mandrel is deposited in mandrel trough 14.The mandrel bar of the mill, moving from right to left but not shown,picks up this mandrel. A hot billet advances through the mill from leftto right between rolls 10 and 12, passes over the mandrel and thus ispierced, and moves on into the mandrel trough, from which itsubsequently discharges sidewise onto skids 15. ln the meantime themandrel bar is retracted, leaving the now heated mandrel resting in theguide shoe 13. A cooling bosh 16 is situated beside the mandrel troughon the opposite side from skids and has water sprays 17. The heatedmandrel is removed from the guide shoe and placed in the bosh and thuscooled for another piercing. The parts thus far described can be of anystandard or desired construction, and therefore are not shown nordescribed in greater detail.

The apparatus of the present invention includes a verti cal column 19which is situated adjacent the mandrel trough 14, preferably on the sameside asthe cooling bosh 16. This column has a thrust bearing 19 andcarries a sleeve 20 which rests on said thrust bearing and is rotatableon a vertical axis. Said sleeve carries a short, radially extending boom21, which is fixed thereto, as by gussets 22. Boom 21 carries a longer,longitudinally extending boom 23. Preferably a structural member 24connects the free extremity of boom 23 and the top of sleeve 29 torigidity these parts. Column 18 is positioned and boom 21 dimensioned sothat boom 23 can occupy a position directly over the mandrel trough 14but also can swing to either side thereof.

ice

Boom 23 serves as a trackway for a carriage 25, which has wheels 26riding on anges on said boom` A doubleacting fluid pressure cylinder 27is fixed to the boom and contains a reciprocable piston and piston rod28. The free end of said piston rod is connected to carriage 25 at 29 sothat application of pressure to cylinder 27 either projects or retractssaid carriage along boom 23.

A frame 30 is pivoted to carriage 25 at 31. A doubleacting lluidpressure cylinder 32 is pivoted to said carriage at 33 and contains areciprocable piston and piston rod 34. The free end of said piston rodis pivoted to frame 30at 35, so that application of pressure to cylinder32 moves frame30 up or down about its pivot 31.

Frame 39 carries cooperating fixed and movable mandrel engaging jaws 36and 37 respectively. The latterrjaw is pivoted to the frame at 38 andhas an operating lever 39extending from the opposite side of its pivot.Frame 30 has-an overhanging ear 40. A double-acting fluid pressurecylinder 41 is pivoted to said ear at 42 and contains a reciprocablepiston and piston rod 43. The free end of said piston rod is pivoted tothe free end of the operating lever 39 at 44` so that application ofpressure to cylinder 41 opens or closes jan/S36 and 37.

For swinging the boom 23 about therpivot on column 18, the apparatusincludes a motor driven winch 45,' (Figure 3) a cable 46 wrapped aroundsaid winch and connected to the free end of said boom, a second cable 47connected to the free end of the boom and extending in the oppositedirection, and a counterweight 48 at the end of the latter cable. Forguiding cable 46 between the winch and boom, the apparatus includes ahollow vertical column 49 which is situated above the winch and has asheave 5t) at its upper end. The cable extends up through this column,around sheave 50, and thence to the free end of the boom. Similarly forguiding cable 47 between the boom and counterweight, the apparatusincludes a vertical column 51 which has a sheave 52 at its upper end.Cable 47 extends from the free end of the boom, around sheave 52, anddown through column 51 to the counterweight. Winch 45 can be rotated ineither direction. When it winds cable 46, it swings boom 23counterclockwise, as viewed in Figure l. When it un* winds cable 46, thepull of the counterweight 48 on cable 47 swings boom 23 clockwise.

Skids 15 carry an inclined mandrel supporting table 53. A retractablestop 54 is pivoted at 55 to the lower part of said table, and whenprojected retains a mandrel on the table. A double-acting iluid pressurecylinder 56 is pivoted to said table at 57 and contains a reciprocablepiston and piston rod 58. The free end of piston rod 58 is pivoted tothe lower end of stop 54. Application of pressure to cylinder 56 thuseither projects or retracts stop 54. When the stop is retracted, themandrel retained thereby rolls down into the mandrel trough 14 in aposition to be picked up by the mandrel bar of the mill, as alreadyexplained. Pierced lengths of tubing travel far enough to the right inthe mandrel trough so that table 53 does not interfere with theirremoval to the skids 15.

In operation, assume that the mill has just pierced a billet and aheated mandrel M1 is resting on the guide shoe 13 and a cooled mandrelM4 on the inclined table 53. Cylinder 27 is operated to retract carriage25, cylinder 32 to raise the frame 30, cylinder 41 to open the jaws 37and 38, and winch 45 to swing the boom 23 to a position directly overthe mandrel trough 14. Next cylinder 32 is operated to lower the frame30, and cylinder 27 to project the carriage 25. This operation moves thexed jaw 36 within the mandrel bore. Next cylinder 4l is operated toclose the jaws and thus grip the mandrel, cylinder 32 to raise the frame3l) and the mandrel, cylinder 27 to retract the carriage 25 and themandrel, and winch 45 to swing the boom 23 counterclockwise. Thesemovements are coordinated to place the mandrel opposite a vacant spacein the cooling bosh 16. Next cylinder 32 is operated to lower the frame30 and the mandrel, cylinder 27 to project the carriage 2S and thusproject the mandrel into this vacant space, and cylinder 41 to open thejaws 37 and 36 and release the mandrel.

In the meantime cylinder 56 is operated to retract stop 54 and thusrelease mandrel M4, which rolls down into the mandrel trough 14. Thecylinder then is operated to project the stop so that the table canreceive and retain another mandrel. Next the carriage, jaws, frame andwinch are operated to grip a cooled mandrel from bosh 16, carry it to aposition above table 53 and deposit it on said table.

From the foregoing description it is seen that the apparatus of thepresent invention affords a simple and reliable means for mechanicallyhandling and changing mandrels in a seamless tubing piercing mill. Theapparatus can be installed in conjunction with existing mills withoutotherwise altering their structure, and it effectively eliminates theneed for handling mandrels manually.

While I have shown and described only a preferred embodiment of theinvention, it is apparent that modifications may arise. Therefore I donot wish to be limited to the disclosure set forth but only by the scopeof the appended claim.

I claim:

An apparatus comprising an upright column, a first horizontal boomextending from and carried by said column for rotation thereabout, asecond horizontal boom extending at right angles to and rigidly carriedby said first boom at the free end thereof and movable therewith, saidsecond boom being horizontally offset from said column by the length ofsaid rst boom leaving the space beneath said second boom unobstructed,means connected to one of said booms for rotating them about saidcolumn,

a carriage movably supported on said second boom, a double-acting uidpressure cylinder and piston on said second boom and connected to saidcarriage for projecting and retractng the latter with respect to saidrst boom, a frame pivoted to said carriage and having a free end adaptedto be raised and lowered relative to said carriage, a double-acting uidpressure cylinder and piston connected to said carriage and said framefor raising and lowering the free end of said frame, a pair of mandrelgripping jaws carried by the free end of said frame and being relativelymovable on a horizontal axis, and a double-acting uid pressure cylinderand piston connected to said frame and one of said jaws for opening andclosing said jaws.

References Cited in the le of this patent UNITED STATES PATENTS 184,168Nickle Nov. 7, 1876 426,046 McCleane et al Apr. 22, 1890 744,071 HaywardNov. 17, 1903 1,302,861 Schott May 9, 1919 1,764,736 Lowy June 17, 19302,191,143 Hiatt Feb. 20, 1940 2,583,834 Gross Ian. 29, 1952 FOREIGNPATENTS 503,970 France Mar. 29, 1920

